indian paving and cement dust! Help!

[3greens]

Hi all, great site! I needed to re point some indian paving patio which I know was never treated with a sealant. The pointing/ grouting was completely ruined so I spent a week cleaing out all of the joints. My mate?? is a builder and told me to brush in the joints with a dry mix of building sand/ cement/ lime...4 sand 1 cement 1 lime . did this, brushed in and packed it in with a jointing iron. then i brushed off every bit of cement mix that i possibly could. Then I watered it with a really fine spray to moisten the mix through.
Now the problem...I left it for 21 days as advised and today I tried to clean the cement dust residue from the paving with a jet washer taking care not to damage the new grouting. The result is No Change....ther is a ehite residue over the entire surface.. Having now read the forum I should have sealed it first of course!!

Anyone know of any rectifying advice...I have attached 2 pictures ..the dark bit is where i t is still wet.
sorry to ramble but the wife is due home friday for easter and she will go mad if it still looks bleached!!
Thanks to allreplies.

 

[DHTiling]

Hello and welcome... try some grout/cement residue remover.... i'm not a fan of brick acid so try this from LTP..

LTP Grout Stain Remover


Description: LTP Grout Stain Remover is the solution for removal of cement and grout residues and is extremely effective against mineral salt formations (efflorescence). Useful for routine cleaning of patios and other outside paved areas, LTP Grout Stain Remover may be used on glazed ceramics, quarry tiles, terracotta and some stone.

Tips: Pick this product if you have cement and grout residues, mineral salt formations, limescale, water marks, dirty patios and other outside areas. Do not use on limestone or when underfloor heating systems are in operation. DO NOT USE ON ACID SENSITIVE SURFACES.

Technical Data Sheet (PDF)




Then depending on what finish you want then you can seal once clean and dry... LTP mattstone will leave the tiles a normal finish or LTP colour enhancer will darken and enrich the colours..

 

[3greens]

WOW that was quick...thanks Dave...bit of a conflict as this is indian limestone or sandstone paving will your suggestion be Ok with the above?

 

[Ajax123]

try with different types of weak acid first. As far as I remember LTP is a phosphoric acid solution. This is relatively strong and will deffo remove the cement but it may also affect the finish on the limestone. Not sure. I think I would try acetic acid (malt viniger) or citric acid first.

 

[Ajax123]

Correction - LTP is hydrochloric acid which is seven stronger than phosphoric...

 

[DHTiling]

Looking at the pics , i presumed it was Sandstone.. if it is Limestone then deffo do not use the above.. Use Grimex instead..

 

[The Legend; Phil Hobson RIP]

Hi and:welcome:

 

[Perry]

It's sandstone lol try a little brick acid diluted on one tile out of the way and see how it looks

 

[3greens]

Hi PJC, thanks everyone for your help...I thought about everything for a while and tried Sarsons Pickling vinegar as a weak acid. I sprayed it on undiluted and left it for 20 minutes then hosed it off. Has worked brillaintly without affecting the colour of the stone and was very cheap to do!
Success and thanks ofr all the advice.

 

[Dan]

Welcome aboard either way. I'll leave the advice to the professionals.